Container base



FIG. 1 is a top perspective view of the container base of the present invention;

FIG. 2 is a bottom perspective view of the container base of FIG. 1;

FIG. 3 is a side view of the container base of FIG. 1; and,

FIG. 4 is a bottom view of the container base of FIG. 1.

The broken lines shown in the drawings are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a container base, as shown and described. 